In this specification, the terminology “absorptive product” is used to include products which handle all forms of feces or urine, including diapers for nursing infants or caregivers, as well as incontinence products for adults.
According to a report entitled “Diaper Rash Phenomenon” by Kazuya Yamamoto in pages 949 through 956 of “Dermatology 30 (1998)”, the cause and occurrence mechanism of diaper rash is that, (i) ammonia is generated by a mixture of urine and feces, (ii) the ammonia creates an alkaline environment, (iii) enzymes in the feces are strongly activated in the alkaline environment, (iv) these enzymes and ammonia create inflammation in areas where the skin is weak, causing diaper rash. It was pointed out that weak areas of the skin are caused by mechanical stimulation when the materials which comprise the diaper contact the skin, or where the humid environment inside of the diaper causes the skin to become swollen.
The causes of diaper rash explained above are being eliminated by improved performance relating to advancement in the technology of super-absorbent polymer materials. For instance, by rapidly absorbing urine and minimizing dispersion after urination, it has become possible to minimize mixing with feces even if there has been excretion. Furthermore, by using a gas permeable sheet, the stuffy conditions inside the diaper are relieved, which is effective in preventing swelling of the skin. Because of advancements of these countermeasures for diaper rash, occurrences of skin problems such as rashes arising from the use of so-called disposable diapers are becoming less prevalent.
However, if the urine and feces are excreted at about the same time, these countermeasures are still inadequate for preventing inflammation when the stools are soft. For soft stools in particular, even if the feces and urine do not mix, there will be a significant negative affect on the skin if left unattended. This is because soft stools do not easily pass through the top sheet of the diaper that is in contact with the skin, so that while a portion of the liquid content moves to the absorber, the stool remaining on the top sheet adheres to the buttocks of the wearer. Therefore, although there will be no skin problems, cleanup of the buttocks will be difficult when the diaper is changed.
Therefore, in order to prevent the mixing of feces and urine, and also to prevent the adherence of feces to the buttocks, a diaper is proposed which is constructed such that openings are made in the top sheet and the skin contact sheet of the diaper so that the feces can be moved to the outside, and the urine and feces can remain separated. However, because there is no mechanism to maintain the configuration of the top sheet or the skin contact sheet, depending upon the position the diaper is worn, it is difficult to maintain these openings in an open configuration.
In order to resolve these problems, diapers which separate the urine and the feces have been proposed in (a) Tokkai S61-41304 Official Bulletin, (b) Jikkai H6-5614 Official Bulletin, (c) Jikkai H6-11723 Official Bulletin, (d) Utility Model Registration 2559050 Official Bulletin, and (e) Tokuhyo H10-513072 Official Bulletin.
The diaper disclosed in (a) Tokkai S61-41304 Official Bulletin has a long opening at the center of the top sheet running in the lengthwise direction, and by adding an elastic material along the edge of the opening, the top sheet can be made firm so that the opening does not close.
The diaper disclosed in (b) Jikkai H6-5614 Official Bulletin has a concave section extending from below an opening in the top sheet, and a valve which extends the top sheet from the perimeter of the opening to the center area such that the separated feces is prevented from returning by the opening.
The diaper disclosed in (c) Jikkai H6-11723 Official Bulletin has a first top sheet overlying a second top sheet, and there are several elastic members so that the opening which is formed in the center region of and running in the lengthwise direction of the second top sheet is pulled open in the widthwise direction.
The disposable diaper disclosed in (d) Utility model registration 2559050 Official Bulletin with an absorbent panel between a liquid permeable inner sheet and a liquid non-permeable outer sheet, has a second liquid permeable inner sheet which overlies the first liquid permeable inner sheet and has openings facing the anus and the urinary organs of the wearer, and also has a space formed between these two inner sheets.
The disposable absorptive product disclosed in (e) Tokuhyo H10-513072 Official Bulletin has a hole facing the anus and/or the urinary organs of the wearer, and the absorbent material is formed with a pocket to receive the stool or urine.
However, the prior art shown above also has the following problems.
For the diapers shown in (a) Tokkai S61-41304 Official Bulletin and (b) Jikkai H6-5614 Official Bulletin, when observations on their actual use were made, it was seen that the crotch region of the diaper would be shifted toward the center by both thighs of the wearer, and would hang down rather than contact the skin. In other words, with these diapers a problem occurred where, because the crotch portion of the top sheet or surface sheet (hereafter referred to as “top sheet”) was not in tight contact with the crotch of the wearer, the opening made in the top sheet was not effective, and the feces would be spread out across the top of the top sheet. Even if the position of the opening in the top sheet and the anus of the wearer were in line with each other, the opening would be a closed condition because the top sheet was not in close contact with the crotch of the wearer, and it is thought that the feces could not be directed between the top sheet and the back sheet through the opening.
The diaper disclosed by (c) Jikkai H6-11723 Official Bulletin also has a similar problem where the opening is only opened in the widthwise direction, so depending on the way that it is worn, the opening may be forced closed, and fundamentally, the function of the opening cannot be sufficiently shown.
Also, with the disposable diaper disclosed in (d) Utility model registration 2559050 Official Bulletin, while adhesion of urine and feces to the buttocks region can be minimized, the mixing of urine and feces cannot be prevented, and the contamination of the buttocks region by these products cannot be eliminated.
Furthermore, when disposing of stools with the disposable absorptive product disclosed in (e) Tokuhyo H10-513072 Official Bulletin, it is necessary to dispose of the whole disposable absorptive product, and if urine has not been excreted, the urine absorbing function cannot be effectively used and is disposed of as well. These types of problems are applicable to any of the above mentioned conventional diapers.